Take my timezone as an example (AEST):
function parseDate(str_date) {
return new Date(Date.parse(str_date));
}
var str_date = "2015-05-01T22:00:00+10:00"; //AEST time
var locale_date = parseDate(str_date);
locale_date: Fri May 01 2015 22:00:00 GMT+1000 (AEST)
var str_date = "2015-05-01T22:00:00+00:00" //UTC time
var locale_date = parseDate(str_date);
locale_date: Sat May 02 2015 08:00:00 GMT+1000 (AEST)